Stereo Reel to Reel Tape Recorder (1975-77)
The 4000DB is an attractively designed compact tape deck offering multiple connections and controls and quality features among which are Akai's one micron gap heads for high density recording and the well known Dolby Noise Reduction System.
Akai's one-micron gap head is responsible for an amazingly important difference in tape recording. It's the difference between ordinary performance and high density quality recording and playback. Ordinary head gaps are from 2 to 4 microns, but the gap of this outstanding head is only one micron. This high density recording system provides excellent frequency response and clear, high pitched sound is generated as a frequency tone and recorded smoothly without distortion.
Dolby Noise Reduction
With the Dolby Noise Reduction System, hissing noise heretofore thought impossible to eliminate, is reduced to a completely inaudible level. Basically, this circuit boosts the low level signals prior to recording and lowers them by precisely that same amount at playback time. During this revolutionary process, the extraneous noise is eliminated, thus also eliminating tape hiss.
A Tape Monitor Switch and three heads facilitate instant comparison of the recording being made with source signals. Easy confirmation of recording quality results in a more professional recording. The 4000DB is also equipped with a front panel headphone jack for monitoring or private headphone listening.
Sound on Sound Recording
Sound-On-Sound is the accumulation of as many individual recordings on a single track as is desired. For instance, record on track 1 and rewind tape. While monitoring the first recording through headphones, record on track 3. Both recordings will merge on track 3. Repeat as many times as is desired by switching Track Selector positions. Convenient for fun or professional use.
Sound with Sound
Record on one track, then rewind tape and record on another track while listening to first recording through headphones. Playback and compare! Especially convenient for repetition and comparison exercises such as when studying a foreign language, etc.
Independent line and microphone recording level controls and input jacks enable signals from microphone and line sources to be blended and recorded simultaneously. Record your own vocal style accompanied by your favourite orchestra, etc. Interesting and entertaining.
Automatic Shut Off
Threading the tape through the Automatic Shut-Off Lever and setting the Power Switch to Shut-Off position is all that is necessary to effect Automatic Shut-Off at the end of the tape. A convenient safety feature should the unit be left unattended.
Momentarily stops tape travel during recording or playback. Pause control is especially useful when editing tapes. Simply lift Pause Lever when a certain portion of the program is not desired. Easy Start Button release.
Internally illuminated expanded scale VU Meters provide quick and accurate determination of recording and playback levels.
In keeping with Akai's top quality parts utilization policy, the 4000DB also features robust construction and sturdy mechanism. Further, a highly efficient induction type motor assures stable tape travel and ideal starting torque. The characteristics of this motor coupled with a boldly designed flywheel reduces wow and flutter significantly.
Track system: 4-track, 2-channel, stereo/monaural system
Heads: 1 x record, 1 x playback, 1 x erase
Motor: 1 x 4-pole induction
Reel size: up to 7 inch reel
Tape speeds: 3 3⁄4 7 1⁄2 ips
Wow and flutter: 0.15% (7 1⁄2 ips)
Frequency response: 30Hz to 23kHz (7 1⁄2 ips)
Signal to Noise Ratio: 55dB
Total harmonic distortion: 1%
Input: 70mV (line), 0.4mV (mic)
Output: 0.775V (line)
Semiconductors: 27 x transistors, 2 x FET, 4 x IC, 17 x diodes
Dimensions: 406 x 325 x 196mm
service manual - Norbechini
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Reviewed Sep 03rd, 2016 by lowlow007
Low price reel to reel but great sound, 2 speed.
Reviewed Dec 26th, 2014 by Lolek
Operation of each function is perfect, recording on different tapes gives a very good and sometimes excellent results. Not noisy engine and soft operation of the switches give you big comfort operation.Natural voice with very good bass.